It's Elemental - The Element Mendelevium It's Elemental Melting Point: 1100 K (827°C or 1521°F) Boiling Point: Unknown Phase at Room Temperature: Solid Element Classification: Metal Period Number: 7 Group Number: none Group Name: Actinide Radioactive and Artificially Produced What's in a name? Named after the Russian chemist Dmitri Mendeleyev. Say what? Mendelevium is pronounced as men-deh-LEE-vee-em. History and Uses: Mendelevium was first produced by Stanley G. Thompson, Glenn T. Seaborg, Bernard G. Harvey, Gregory R. Choppin and Albert Ghiorso working at the University of California , Berkeley, in 1955. They bombarded atoms of einsteinium -253 with helium ions using a device known as a cyclotron . This produced atoms of mendelevium-256, an isotope with a half-life of about 77 minutes, and a free neutron .

Mendelevium's most stable isotope , mendelevium-258, has a half-life of about 51.5 days. It decays into einsteinium -254 through alpha decay or decays through spontaneous fission. Since only small amounts of mendelevium have ever been produced, it currently has no uses outside of basic scientific research. Estimated Crustal Abundance: Not Applicable Estimated Oceanic Abundance: Not Applicable Number of Stable Isotopes: 0 ( View all isotope data ) Ionization Energy: 6.58 eV Mendelevium»the essentials [WebElements Periodic Table] CAS Registry ID : 7440-11-1 Mendelevium: historical information Mendelevium was discovered by Glenn T. Seaborg, Albert Ghiorso, Bernard Harvey, Gregory Choppin, Stanley G. Thompson in 1955 at USA. Origin of name : named after Dimitri "Mendeleev", the Russian chemist who contributed so much to the development of the periodic table.

Mendelevium, the ninth transuranium element of the actinide series to be discovered, was first identified by Seaborg and others in 1955 as a product of the bombardment of the einsteinium isotope 253Es with helium ions. The isotope produced was 256Md, which has a half-life of about 11/4 hours. Mendelevium around us Mendelevium has no biological role. Mendelevium is a synthetic element that is not present in the geosphere. Abundances for mendelevium in a number of different environments. More abundance data » Location Dmitri Mendeleev – inventor of periodic law Category : Personalities Published by : Data Research Analyst, Worldofchemical Biography & Contributions Dmitri Mendeleev, a Russian chemist and Nobel laureate born on February 08, 1834 – died on February 02, 1907. Mendeleev was formulator of periodic law for elements and created his own version of periodic table elements.

On November 22, 1875 Mendeleev predicted qualities of three new elements like ekasilicon, ekaaluminium and ekaboron ( germanium , gallium and scandium respectively). Element 101 Md (Mendelevium) named after him. He also investigated the composition of petroleum and worked on capillarity of liquids phenomenon. In the field of physical chemistry he investigated the expansion of liquids with heat and devised a formula similar to Gay-Lussac's law. He invented pyrocollodion, a kind of smokeless powder based on nitrocellulose. Dmitri Mendeleev considered as father of periodic table, for the following reasons like He arranged elements into their correct places in the table. Mendeleev corrected relative atomic mass of the elements. Predicted properties of five elements and their compounds Mendeleev was received Davy medal of the Royal Society in the year of 1882, Copley medal in the year of 1905, Nobel Prize for periodic law in the year of 1906. Facts about germanium Germanium is considered as a semi-metal. It is a very important semiconductor material.

Germanium has been found in the atmosphere of Jupiter and in distant stars. Germanium is available through the treatment of germanium dioxide (GeO2) with carbon or hydrogen. Germanium is widely distributed in ores of other metals, such as zinc, and that which is required for manufacturing purposes is recovered as a by-product from the flue-dusts of zinc smelters. Germanium used as an alloying agent and as a catalyst, infrared spectroscopes and infrared detectors. Facts about gallium Gallium is the only metal, except for other periodic table elements like mercury , caesium, and rubidium, which can be liquid near room temperatures. Gallium easily alloys with most metals and has semiconductor properties. Gallium compounds like Gallium arsenide are used in semiconductor production i.e., laser diodes, light-emitting diodes and solar panels. It is also used to create brilliant mirrors.

To contact the author mail: articles@worldofchemicals.com © WOC Article Dmitri Mendeleev – creator of first periodic table Category : Personalities Published by : Data Research Analyst, Worldofchemical Biography & Contributions Dmitri Mendeleev, a Russian chemist and Nobel laureate born on February 08, 1834 – died on February 02, 1907. Mendeleev was formulator of periodic law for elements and created his own version of periodic table elements. On November 22, 1875 Mendeleev predicted qualities of three new elements like ekasilicon, ekaaluminium and ekaboron ( germanium , gallium and scandium respectively). Element 101 Md ( Mendelevium ) named after him. He also investigated the composition of petroleum and worked on capillarity of liquids phenomenon. In the field of physical chemistry he investigated the expansion of liquids with heat and devised a formula similar to Gay-Lussac's law. He invented pyrocollodion, a kind of smokeless powder based on nitrocellulose.

Dmitri Mendeleev considered as father of periodic table, for the following reasons like He arranged elements into their correct places in the table Mendeleev corrected relative atomic mass of the elements Predicted properties of five elements and their compounds Mendeleev was received Davy medal of the Royal Society in the year of 1882, Copley medal in the year of 1905, Nobel Prize for periodic law in the year of 1906. Gay-Lussac's law Gay-Lussac's law is defined as pressure of a sample of gas at constant volume, is directly proportional to its temperature in Kelvin. Facts about germanium Germanium is considered as a semi-metal. It is a very important semiconductor material. Germanium has been found in the atmosphere of Jupiter and in distant stars. Germanium is available through the treatment of germanium dioxide (GeO2) with carbon or hydrogen. Germanium is widely distributed in ores of other metals, such as zinc, and that which is required for manufacturing purposes is recovered as a by-product from the flue-dusts of zinc smelters. Germanium used as an alloying agent and as a catalyst, infrared spectroscopes and infrared detectors.

Facts about gallium Gallium is the only metal, except for other periodic table elements like mercury, caesium, and rubidium, which can be liquid near room temperatures. Gallium easily alloys with most metals and has semiconductor properties. Gallium compounds like Gallium arsenide are used in semiconductor production i.e., laser diodes, light-emitting diodes and solar panels. It is also used to create brilliant mirrors. To contact the author mail: articles@worldofchemicals.com © WOC Article 1955 Albert Ghiorso and co-workers, Berkeley, Calif., USA пїЅ. пїЅ. пїЅпїЅпїЅпїЅпїЅпїЅпїЅпїЅпїЅ (D.I. Mendeleyev) (1834-1907) History & Etymology First prepared in 1955 by Albert Ghiorso, Bernard G. Harvey, Gregory R. Choppin, Stanley G. Thompson, and Glenn T. Seaborg at the Berkeley Laboratory of the University of California by bombardment of Einsteinium with Helium ions.

In his autobiography, Seaborg says about the naming of Mendelevium (note) : We thought it fitting that there be an element named for the Russian chemist Dmitri Mendeleev, who had developed the periodic table. In nearly all our experiments discovering transuranium elements, we'd depended on his method of predicting chemical properties based on the element's position in the table. But in the middle of the Cold War, naming an element for a Russian was a somewhat bold gesture that did not sit well with some American critics. Originally, the suggested chemical symbol was Mv, later this is changed to Md. The name and symbol Mendelevium (Md) was ratified by the International Union of Pure and Applied Chemistry (IUPAC) Council meeting in Geneva during August 1997 (See "Naming the transfermium elements" ). In 1980, at the symposium Commemorating the 25th Anniversary of the Discovery of Mendelevium, Glenn T.

Seaborg recalls the following anecdote, which was published in the Daily Cal at the time of the discovery of element #101: "The University of California Nuclear Metaphysical Laboratories have announced a startling new finding in the world of atomics. The new discovery is an entirely novel element named 'Percentium' by its discoverer, the 15 1/2 year old Leonardo da Vinci. The element, number 101 in the atomic series, follows element number 100, 'Centium.' The youthful da Vinci said that this was the reason for the new element's name, Percentium. 'The interesting fact about Percentium,' said Moosbrugger, 'is that it has a negative half-life. That is,' he went on, 'its radioactivity and total mass increase 1 percent every 100 years. Probably it is the first of a series of elements that spontaneously integrates the successive members of the series.'" (this is not all, read the pdf-file, available on-line ). New name John and Gordon Marks suggested in 1994 the name Bohemium (Bo) after Bohemia, where the actinides were first mined, cf.

thulium after Thule where the lanthanides were first mined. The Marks brothers found the old names ugly and confusing. They offered alternative names that are equivalent contemporary (at the time and place of discovery) metaphors, both more euphonious and more memorable (note) . Dmitrij Ivanovič Mendeleev Дмитрий Иванович Менделеев (Dmitrij Ivanovič Mendeleev)(Verhnie Aremzyani village, near Tobolsk, 8 February [O.S. 27 January] 1834 пїЅ Saint Petersburg 2 February [O.S. 20 January] 1907), Russian chemist and inventor. Between 1859 and 1861, he worked on the capillarity of liquids and the workings of the spectroscope in Heidelberg. In late August 1861 he wrote his first book on the spectroscope. He became Professor of Chemistry at the Saint Petersburg Technological Institute and Saint Petersburg State University in 1863. In 1865 he became Doctor of Science for his dissertation "On the Combinations of Water with Alcohol".

He achieved tenure in 1867, and by 1871 had transformed Saint Petersburg into an internationally recognized center for chemistry research. Though Mendeleev was widely honored by scientific organizations all over Europe, including the Copley Medal from the Royal Society of London, he resigned from Saint Petersburg University on 17 August 1890. In 1893, he was appointed Director of the Bureau of Weights and Measures. It was in this role that he was directed to formulate new state standards for the production of vodka. As a result of his work, in 1894 new standards for vodka were introduced into Russian law and all vodka had to be produced at 40% alcohol by volume. Mendeleev also investigated the composition of oil fields, and helped to found the first oil refinery in Russia. In 1905, Mendeleev was elected a member of the Royal Swedish Academy of Sciences. The following year Nobel Committee for Chemistry recommended to the Swedish Academy to award the Nobel Prize in Chemistry for 1906 to Mendeleev for his discovery of the periodic system (see History of the Chemical Symbols ). The Chemistry Section of the Swedish Academy supported this recommendation.

The Academy was then supposed to approve the Committee choice as it has done in almost every case. Unexpectedly, at the full meeting of the Academy, a dissenting member of the Nobel Committee, Peter Klason, proposed the candidacy of Henri Moissan whom he favored. Svante Arrhenius, although not a member of the Nobel Committee for Chemistry, had a great deal of influence in the Academy and also pressed for the rejection of Mendeleev, arguing that the periodic system was too old to acknowledge its discovery in 1906. According to the contemporaries, Arrhenius was motivated by the grudge he held against Mendeleev for his critique of Arrhenius's dissociation theory. After heated arguments, the majority of the Academy voted for Moissan. The attempts to nominate Mendeleev in 1907 were again frustrated by the absolute opposition of Arrhenius (note). He is credited as being the creator of the first version of the periodic table of elements. Using the table, he predicted the properties of elements yet to be discovered..

Mendelevium - Element information, properties and uses | Periodic Table Chemistry in its element: mendelevium (Promo) You're listening to Chemistry in its element brought to you by Chemistry World, the magazine of the Royal Society of Chemistry. (End promo) This week's element pays tribute to the creator of the periodic table. Here's Hayley Birch: Hayley Birch In 1933, Albert Einstein was visiting a friend at the University of California, Los Angeles, when he was introduced to an aspiring scientist by the name of Glenn Theodore Seaborg. Seaborg was studying chemistry and was only an undergraduate, but Einstein took the time to talk to him and encourage him in his scientific endeavours. This meeting seems to have had a profound effect on the young Seaborg, who went on, like Einstein, to become a Nobel Prize winner and wrote in a tribute many years later that he had been much impressed by the great man's modesty and kindness. He also remarked upon Einstein's dedication to peace and was perhaps inspired by him in his own attitude to war.

Despite playing a central role in the creation of the atomic bomb by helping to separate plutonium from uranium, he is said to have remained a pacifist and believed that nuclear energy should be used only for good. By what appears to have been pure coincidence, it was on the day of Einstein's death - the 18 April 1955 - that the American Physical Society received a paper from Seaborg and his colleagues at the University of California, Berkeley, announcing the discovery of a new radioactive element that was to become known as mendelevium. At its most stable atomic weight of 258, it is considered one of the 'superheavy'-weights of the periodic table. Like most of the heavier elements, it's so large that it has trouble sticking itself together and usually decays after just a couple of hours - which is why Seaborg and his colleagues had to create it synthetically. Considering his contribution to the Manhattan project, mendelevium was certainly not Seaborg's most significant achievement.

It was not even his first element: he was part of a team based at the Radiation Laboratory that had already announced the discovery of americium and curium, as well as berkelium and californium, named after his own university. Four years previously he had been awarded the Nobel Prize, along with Edwin McMillan, for these very achievements, lumped together under what they called the trans-uranium elements - because they had atomic numbers higher than uranium. At atomic number 101, mendelevium was a different type of element: the first of the trans-fermium elements. But to make it, Seaborg employed the same piece of equipment - the particle accelerator that had been used to chemically identify plutonium after it was discovered by Enrico Fermi during the Second World War. The '60-inch Cyclotron', as it was called, was built according to the design of Ernest Lawrence, another of Seaborg's colleagues from the Manhattan project, and had already been in operation for well over a decade. When it was finally decommissioned in 1962, it was hailed as the 'most productive atom-smasher in history'.

To make their synthetic element, Seaborg's team began with a tiny amount of another element, one which had first shown up in the fallout of a nuclear test carried out by the US in 1952. This other element was later to become einsteinium but it appears in the mendelevium paper as simply '99', accompanied by its isotope number, 253. The team used the cyclotron to smash helium ions into their 'element 99' and produce just a few atoms - 17, to be precise - of mendelevium. Even since its discovery, so little mendelevium has ever been produced that scientists haven't had a chance to find a use for it. In the Physical Review paper announcing their discovery, Seaborg and his colleagues paid tribute to yet another great scientist. As they wrote: "We would like to suggest the name mendelevium...

in recognition of the pioneering role of the great Russian chemist, Dmitri Mendeleev, who was the first to use the periodic system of the elements to predict the chemical properties of undiscovered elements." And perhaps there is no more fitting time in this series to pay our own tribute to Mendeleev, who is, after all, the man responsible for the periodic table on which the Chemistry in its element podcast is based. Brought up in Russia, Mendeleev was the sort of person who, it seems, was incapable of sticking to one discipline and as well as serving as the director of the Russian institute for weights and measures, had a hand in developing the Russian oil industry. Given all this, it's perhaps less surprising than it ought to be that he conceived of the Periodic Table on the same day that he was supposed to be inspecting a cheese factory. And so, in mendelevium, Mendeleev got his element and, eventually, so did Seaborg, whom element 106 is named for. Meera Senthilingham So, both Mendeleev and Seaborg got their elements in the end. That was science writer Hayley Birch, bringing us the atom-smashing chemistry of mendelevium.

Now, next week, continuing along the lines of smashing atoms, we go one step further and experience elemental warfare. Simon Cotton In the days of the Cold War, America and Russia rivalled each other in all sorts of ways. Never mind thermonuclear bombs and intercontinental ballistic missiles to deliver them, they competed in putting men and women into space; who could win the most medals in the Olympic Games; and in making new chemical elements. In the case of element 105, the controversy went on for nearly 30 years and was part of the so-called 'Transfermium Wars', when no blood was spilt but a great deal of ink was. In the Red corner, the Soviet team at the Joint Institute for Nuclear Research at Dubna, near Moscow, led by Georgy Flerov. In the Blue corner, the American team at the University of California at Berkeley, led by Albert Ghiorso. Meera Senthilingham And to find out which side came through with the chemistry (and name) of element 105, dubnium, join Simon Cotton for next week's chemistry in its element. Until then, I'm Meera Senthilingham and thank you for listening.

(Promo) Chemistry in its element is brought to you by the Royal Society of Chemistry and produced by thenakedscientists.com . There's more information and other episodes of Chemistry in its element on our website at chemistryworld.org/elements . (End promo) Element of the week: mendelevium | video | @GrrlScientist | Science | The Guardian Share on Messenger Close This week's element is mendelevium, which has the atomic symbol, Md and the atomic number 101. This element was named in 1955 in honour of Russian chemist, Dmitri Ivanovich Mendeleev, who produced one of the first periodic tables of the elements. Originally, this element's official symbol was "Mv" but two years later, it was changed to "Md" by The International Union of Pure and Applied Chemistry ( IUPAC ), which is the official international body for chemistry. Mendelevium is an actinoid that can synthesised in the lab by bombarding einsteinium -253 with alpha particles ( helium nuclei).

This element has never been produced in quantities that are visible to the naked eye and indeed, this element was discovered from just 17 atoms that had been synthesised in a cyclotron by the group in Berkeley. Mendelevium is predicted to be a silvery metal that is solid at room temperature. Mendelevium was identified from an isotope based recording its spontaneous decay into one of its daughter elements, fermium -256 or einsteinium -254. On the night of its discovery, radioactive decay events were recorded for three individual atoms before the fourth event provided enough evidence to officially identify this isotope as belonging to element 101. Additional analysis and experimentation showed this particular isotope had a mass 256 and it spontaneously decays by electron capture after a half-life of 78.1 minutes. The isotopes of mendelevium range from Md-245 to Md-260, based on their atomic weights. Sixteen of these isotopes have been characterised so far: the most stable are Md-258 (half-life: 51.5 days) and Md-260 (half-life: 31.8 days).

None of its other isotopes have been predicted to have longer half-lives and so far, its other isotopes all have decreasingly shorter half-lives, many of which are less than 5 minutes. The most interesting thing about Mendelevium is that it is the first element that was produced one atom at a time. This element has no known uses. In this video, our favourite chemistry professors tell us a little about mendelevium: [ Video link ] .. .. .. .. .. .. .. .. .. .. .. .. Video journalist Brady Haran is the man with the camera and the University of Nottingham is the place with the chemists.

You can follow Brady on twitter @ periodicvideos and the University of Nottingham on twitter @ UniofNottingham You've already met these elements: Fermium : Fm, atomic number 100 Einsteinium : Es, atomic number 99 Californium : Cf, atomic number 98 Berkelium : Bk, atomic number 97 Curium : Cm, atomic number 96 Americium : Am, atomic number 95 Plutonium : Pu, atomic number 94 Neptunium : Np, atomic number 93 Uranium : U, atomic number 92 Protactinium : Pa, atomic number 91 Thorium : Th, atomic number 90 Actinium : Ac, atomic number 89 Radium : Ra, atomic number 88 Francium : Fr, atomic number 87 Radon : Rn, atomic number 86 Astatine : As, atomic number 85 Polonium : Po, atomic number 84 Bismuth : Bi, atomic number 83 Lead : Pb, atomic number 82 Thallium : Tl, atomic number 81 Mercury : Hg, atomic number 80 Gold : Au

, atomic number 79 Platinum : Pt, atomic number 78 Iridium : Ir, atomic number 77 Osmium : Os, atomic number 76 Rhenium : Re, atomic number 75 Tungsten : W, atomic number 74 Tantalum : Ta, atomic number 73 Hafnium : Hf, atomic number 72 Lutetium : Lu, atomic number 71 Ytterbium : Yb, atomic number 70 Thulium : Tm, atomic number 69 Erbium : Er, atomic number 68 Holmium : Ho, atomic number 67 Dysprosium : Dy, atomic number 66 Terbium : Tb, atomic number 65 Gadolinium : Gd, atomic number 64 Europium : Eu, atomic number 63 Samarium : Sm, atomic number 62 Promethium : Pm, atomic number 61 Neodymium : Nd, atomic number 60 Praseodymium : Pr, atomic number 59 Cerium : Ce, atomic number 58 Lanthanum : La, atomic number 57 Barium

 : Ba, atomic number 56 Cæsium : Cs, atomic number 55 Xenon : Xe, atomic number 54 Iodine : I, atomic number 53 Tellurium : Te, atomic number 52 Antimony : Sb, atomic number 51 Tin : Sn, atomic number 50 Indium : In, atomic number 49 Cadmium : Cd, atomic number 48 Silver : Ag, atomic number 47 Palladium : Pd, atomic number 46 Rhodium : Rh, atomic number 45 Ruthenium : Ru, atomic number 44 Technetium : Tc, atomic number 43 Molybdenum : Mo, atomic number 42 Niobium : Ni, atomic number 41 Zirconium : Zr, atomic number 40 Yttrium : Y, atomic number 39 Strontium : Sr, atomic number 38 Rubidium : Rr, atomic number 37 Krypton : Kr, atomic number 36 Bromine : Br, atomic number 35 Selenium : Se, atomic number 34 Arsenic : As, atomic number 3

3 Germanium : Ge, atomic number 32 Gallium : Ga, atomic number 31 Zinc : Zn, atomic number 30 Copper : Cu, atomic number 29 Nickel : Ni, atomic number 28 Cobalt : Co, atomic number 27 Iron : Fe, atomic number 26 Manganese : Mn, atomic number 25 Chromium : Cr, atomic number 24 Vanadium : V, atomic number 23 Titanium : Ti, atomic number 22 Scandium : Sc, atomic number 21 Calcium : Ca, atomic number 20 Potassium : K, atomic number 19 Argon : Ar, atomic number 18 Chlorine : Cl, atomic number 17 Sulfur : S, atomic number 16 Phosphorus : P, atomic number 15 Silicon : Si, atomic number 14 Aluminium : Al, atomic number 13 Magnesium : Mg, atomic number 12 Sodium : Na, atomic number 11 Neon : Ne, atomic number 10 Fluorine : F, atomic number 9 Oxygen : O, atomic number 8 Nitrogen : N, atomic number 7 Carbon : C, atomic

 number 6 Boron : B, atomic number 5 Beryllium : Be, atomic number 4 Lithium : Li, atomic number 3 Helium : He, atomic number 2 Hydrogen : H, atomic number 1 Here's the Royal Society of Chemistry's interactive Periodic Table of the Elements that is just really really fun to play with!

.. .. .. .. .. .. .. .. .. .. .. Grrlscientist can also be found here: Maniraptora . She sometimes lurks on social media: facebook , Google + , LinkedIn , Pinterest and of course, she's quite active on twitter: @ GrrlScientist Facts About Mendelevium Facts About Mendelevium October 11, 2013 04:12pm ET MORE Melting Point: 1,521 F (827 C) Boiling Point: Unknown Word Origin: Mendelevium is named after the Russian chemist Dmitri Mendeleev. Discovery: In early 1955, Stanley Thompson, Glenn Seaborg, Bernard Harvey, Gregory Choppin and Albert Ghiorso at the University of California, Berkeley, bombarded Einsteinium-53 with helium ions in the Berkeley 60-inch cyclotron. It produced a new isotope, 256Md, which was notable for revealing the existence of mendelevium and also for being the first isotope synthesized on a one-atom-at-a-time basis. It was the ninth transuranium element of the actinide series to be discovered.

Properties of mendelevium Mendelevium is part of the actinide series . As is characteristic of actinide elements, mendelevium possesses a III oxidation state. Experiments indicate that it also possesses a moderately stable II oxidation state. [See Periodic Table of the Elements ] Mendelevium has 14 recognized isotopes. The most stable one is 258Md, which has a half-life of about 51.5 days. Sources of mendelevium Mendelevium is artificially produced, and it has never been made in great quantities. Uses of mendelevium Only small quantities of mendelevium have ever been produced, so it has no commercial uses. It is used only for scientific research. The isotope 256Md has been helpful in understanding some of the chemical properties of mendelevium in aqueous solution.

Element 101 | Article about Element 101 by The Free Dictionary Element 101 | Article about Element 101 by The Free Dictionary Related to Element 101: Element 102 mendelevium (mĕndəlāv`ēəm), artificially produced radioactive chemical element; symbol Md; at. no. 101; mass no. of most stable isotope 258; m.p. 827&degC;; b.p. and sp. gr. unknown; valence +1, +2, +3. Mendelevium is a metal of the actinide series actinide series, a series of radioactive metallic elements in Group 3 of the periodic table. Members of the series are often called actinides, although actinium (at. no. 89) is not always considered a member of the series. ..... Click the link for more information. in Group 3 of the periodic table periodic table, chart of the elements arranged according to the periodic law discovered by Dmitri I. Mendeleev and revised by Henry G. J. Moseley.

In the periodic table the elements are arranged in columns and rows according to increasing atomic number (see the table entitled ..... Click the link for more information. . The ninth transuranium element transuranium elements, in chemistry, radioactive elements with atomic numbers greater than that of uranium (at. no. 92). All the transuranium elements of the actinide series were discovered as synthetic radioactive isotopes at the Univ. ..... Click the link for more information. to be discovered, it is named for the Russian chemist Dmitri Ivanovich Mendeleev Mendeleev, Dmitri Ivanovich , 1834–1907, Russian chemist. He is famous for his formulation (1869) of the periodic law and the invention of the periodic table, a classification of the elements; with Lothar Meyer, who had independently reached similar conclusions, he was ..... Click the link for more information. . The symbol Mv was used at first, but it was changed to Md in 1963. Sixteen isotopes of mendelevium are known.

Mendelevium-256 (half-life about 76 min) was the first isotope produced; it was detected in 1955 by Albert Ghiorso, Bernard G. Harvey, Gregory R. Choppin, Stanley G. Thompson, and Glenn T. Seaborg Seaborg, Glenn Theodore , 1912–99, American chemist, b. Ishpeming, Mich., grad. Univ. of California at Los Angeles, 1934, Ph.D. Univ. of California at Berkeley, 1937. ..... Click the link for more information. , who produced it one atom at a time by bombarding einsteinium-253 with alpha particles in a cyclotron at the Univ. of California at Berkeley. This technique of producing and detecting single atoms has become the standard for the discovery of the elements beyond mendelevium in the periodic table. Little is known of the properties of this element, since its isotopes are unstable and difficult to produce.

Mendelevium-258 (the most stable isotope) has a half-life of 51.5 days; its synthesis (by bombarding einsteinium-255 with alpha particles) may make possible studies of the physical and chemical properties of the element. mendelevium Mendelevium Origins of the Element Names Mendelevium #101 Mendelevium (Md) was discovered in 1955 by a University of California-Berkeley team of Ghiorso, Harvey, Choppin, Thompson, and Seaborg by bombarding Einsteinium with helium ions. 42He + 25399Es -> 256101Md + 10n Because its half life is about 1.5 hour, it is unlikely to be produced in weighable amounts. It decays by electron capture to Fermium which in turn decays by prominent fission in a half life of about 3 hours.

0-1e + 256101Md -> 256100Fm Its predicted eka-Thulium chemical behavior allowed separation as a +3 ion so that fission of only three atoms of Fermium was sufficient to identify the existence of element #101. The named was chosen to honor the Russian chemist Dmitri Mendeleev who first created the periodic chart. Dmitri I. Mendeleev (1834-1907) was born the youngest of 17 children in Tobolsk, Siberia. He was educated at the University of St. Petersburg (now Leningrad), published his thesis on the Union of Alcohol and Water , then studied in France and Germany. In September 1860 Mendeleev attended the First International Chemical Congress in Karlsruhe (Germany) where 140 prominent chemists met to sort out contradictory lists of atomic and molecular weights. The group failed to reach agreement on the issue. Afterwards Mendeleev visited the first oil fields in Pennsylvania then returned to St. Petersburg where he taught until 1890.

While returning home, Mendeleev, like several other prominent chemists, realized that a syllabus distributed at the Congress by the Italian Stanislao Cannizzaro (1826-1910) demonstrated how Amadeo Avogrado´s hypothesis provided unambiguous atomic and molecular weights. Playing a solitaire-like game with cards each labelled with a chemical element, Mendeleev organized the elements into a table using the new atomic weights and their chemical combining power (valence). This first periodic table provided organization to inorganic chemistry. Trends he noted in families of elements caused him to believe that some atomic weights were erroneous, and permitted him to predict properties for empty positions on his table. In March 1869 Dmitri Mendeleev published a paper on The Relation of Properties to Atomic Weights of the Elements. He proposed precise properties for yet undiscovered elements which he called eka-Aluminum (now #31), eka-Silicon (now #32) and eka-Boron (now #21) after expected similarities to Aluminum, Silicon, and Boron. Within two decades elements were discovered with properties closely matching Mendeleev´s predictions.

These are now called Gallium (found in 1875) and Germanium (found in 1886), and Scandium (found in 1879). Mendeleev wrote Elements of Chemistry in 1868. Mendeleev´s periodic table rapidly became the basis for understanding elements and their compounds. (In 1904 Mendeleev was photographed at home in his study.) Mendeleev made additional predictions: an element lighter than Hydrogen, and possible heavy elements. No element has been found lighter than Hydrogen and Moseley´s X-ray study suggests none is possible. Inadequate knowledge of the rare earths and artificially produced elements misled Mendeleev´s predictions about heavier elements. Mendeleev´s periodic table assisted and was complimented by the discovery of the entire noble gas family of elements. The current position of the actinides (and the artificially synthesized transuranic elements) was not established until Glenn Seaborg found elements #93 and #94 had unexpected solubilities.

But the prominent German chemist, Lothar Meyer (1830-1895), also attended the First International Chemical Congress, realized the value of Avogadro´s hypothesis from Stanislao Cannizzaro´s paper, and created a similar table. Meyer wrote: I also received a copy which I put in my pocket to read on the way home. Once arrived there I read it again repeatedly and was astonished at the clearness... The scales seemed to fall from my eyes. Meyer included a periodic table in a new edition of his book Die modernen Theorien der Chemie (December 1869), but did not make predictions like Mendeleev´s. Both Meyer and Mendeleev believed the other had plagiarized. Eventually both came to realized that they had independently discovered the pattern in the elements. While an inspired teacher, Mendeleev resigned his professorship rather than obey an order to cease interfering with affairs of government. When as part of his attempts to modernize Russia, the Czar declared that all Russians should be beardless, Mendeleev defied the Czar's wishes and refused to cut his hair.

Nevertheless, he won the appointment as Director of the Bureau of Weights and Measures where he worked out the standards for Russian units. Navigate by clicking the graphic chart (just above) or the text table (below)

Question: Element 101, Md, is named after which Russian chemist?
Answer: Mendeleev